Gtranslate for WP is a plugin that will place a translation widget on your site, and allow for instant machine translation into 58 different languages.
Machine translation looks a bit strange to native language speakers, but it's still very useful. The free version of this plugin sends your page through Google Translate. There are also a pro and enterprise version where you can get professional translation done.
I found the installation of this to be a bit confusing. I'm going to show you how to install it so you don't have to spend time scratching your head over the non-standard installation method. Then we'll put a widget on the sidebar and see how it looks.
Step 1: Installation using Plugins > Add New
If you go to Plugins > Add New and search for gtranslate, you only get one choice - grtrans. This is not the actual plugin.
If you install it and then go to its settings you'll get this page. This page has a link to the actual plugin and couple of advertising videos that explain the pro and enterprise versions. Click the link at the top, and download the plugin to your computer.
If you never had installed gtrans, you could have downloaded the free version from the website and skipped these steps. From here it's a normal installation. But you would have no way of knowing that. I would bet that some beginners downloaded gtrans and then abandoned the install when it didn't appear to work.
Step 2: Install the actual plugin
Use the Upload method to install wp_gtranslate.
Step 3: Access the configuration
You will be able to access the plugin from the Settings menu. Notice that both grtrans and GTranslate are both on the menu. To configure this click on GTranslate.
Step 4: Make your setup choices
Choose your configuration options and save.
Step 5: Add the correct widget
Go to Appearance > Widgets to add a widget to your site.
Step 6: Drag and drop the widget to a sidebar
Drag and drop the GTranslate widget to a sidebar.
gtrans has a widget that does nothing except take you to the intro page with the tutorials.
Here's a test site showing the widget installed, and the page translated to Italian.
It's really a pretty simple plugin, but the download method could leave you scratching your head for a while. If you're interested in the professional or enterprise version you can see a comparison chart here to decide what you might need.